Detection of generator stator inter-circuit faults

Abstract

Aspects of the invention provide a system and method for detecting inter-circuit faults within a generator stator. In one embodiment, a computer system includes: a sampler for sampling phase voltages and phase currents of a generator stator; a plurality of pre-defined blocks for enabling, based on the sampled phase voltages and currents, an inter-circuit fault detection scheme; a level detection block for determining, in response to the enabled inter-circuit fault detection scheme, a plurality of differences between the sampled phase voltages; and a comparison logic device for comparing, in response to the enabled inter-circuit fault detection scheme, each of the differences of the sampled phase voltages and determining, based on the differences, an inter-circuit fault within at least one phase of the generator stator. The system may also include a negative sequence voltage block for detection of inter-circuit fault within a generator stator.

What is claimed is: 
     
         1 . A computer system, comprising:
 a sampler for sampling phase voltages and phase currents of a generator stator;   a plurality of pre-defined blocks for enabling, based on the sampled phase voltages and currents, an inter-circuit fault detection scheme;   a level detection block for determining, in response to the enabled inter-circuit fault detection scheme, a plurality of differences between the sampled phase voltages; and   a comparison logic device for comparing, in response to the enabled inter-circuit fault detection scheme, each of the differences of the sampled phase voltages and determining, based on the differences, an inter-circuit fault within at least one phase of the generator stator.   
     
     
         2 . The system of  claim 1 , further comprising a negative sequence over-voltage block for determining, based on the sampled phase voltages, a negative sequence voltage and determining if the negative sequence voltage is greater than a threshold. 
     
     
         3 . The system of  claim 1 , wherein the level detection block further includes: comparing the sampled phase voltages, and determining if an unbalance between the sampled phase voltages is within a pre-defined limit. 
     
     
         4 . The system of  claim 1 , wherein the plurality of pre-defined blocks includes a directional element for determining, based on the sampled phase voltages and currents, if a fault is within the generator stator. 
     
     
         5 . The system of  claim 1 , wherein the plurality of pre-defined blocks includes a ground fault de-sensitizer for determining, based on the sampled phase voltages, if a fault is a ground fault. 
     
     
         6 . The system of  claim 1 , wherein the plurality of pre-defined blocks includes a phase-to-phase fault de-sensitizer for determining, based on the sampled phase voltages, if a fault is a phase-phase fault. 
     
     
         7 . A computer program comprising program code embodied in at least one computer-readable medium, which when executed, enables a computer system to implement a method of detecting inter-circuit faults within a generator stator, the method comprising:
 sampling phase voltages of the generator stator;   sampling phase currents of the generator stator;   enabling, based on the sampled phase voltages and currents, an inter-circuit fault detection scheme;   determining, in response to the enabling, a plurality of differences between the sampled phase voltages; and   comparing, in response to the enabling, each of the differences of the sampled phase voltages and determining, based on the differences, an inter-circuit fault within at least one phase of the generator stator.   
     
     
         8 . The computer program of  claim 7 , further comprising determining a negative sequence voltage, based on the sampled phase voltages, and determining if the negative sequence voltage is higher than a threshold. 
     
     
         9 . The computer program of  claim 7 , further comprising comparing the sampled phase voltages, and determining if an unbalance between the sampled phase voltages is within a pre-defined limit. 
     
     
         10 . The computer program of  claim 9 , wherein comparing each of the differences of the sampled phase voltages is further in response to determining that the balance between the sampled phase voltages is within the pre-defined limit. 
     
     
         11 . The computer program of  claim 7 , further comprising filtering, using a timer block, to ensure isolation of a generator under a sustained inter-circuit fault. 
     
     
         12 . The computer program of  claim 7 , wherein enabling the inter-circuit fault detection scheme further comprises: determining, based on the sampled phase voltages and current, if a fault is within the generator stator. 
     
     
         13 . The computer program of  claim 7 , wherein enabling the inter-circuit fault detection scheme further comprises: determining, based on the sampled phase voltages, if a fault is a ground fault. 
     
     
         14 . The computer program of  claim 7 , wherein enabling the inter-circuit fault detection scheme further comprises: determining, based on the sampled phase voltages, if a fault is a phase-phase fault. 
     
     
         15 . A computer-implemented method for detecting inter-circuit faults within a generator stator, the method comprising:
 sampling phase voltages of the generator stator;   sampling phase currents of the generator stator;   enabling, based on the sampled phase voltages and phase currents, an inter-circuit fault detection scheme;   determining, in response to the enabling, a plurality of differences between the sampled RMS phase voltages; and   comparing, in response to the enabling, each of the differences of the sampled phase voltages and determining, based on the differences, an inter-circuit fault within at least one phase of the generator stator.   
     
     
         16 . The computer-implemented method of  claim 15 , further comprising determining a negative sequence voltage, based on the sampled phase voltages, and determining if the negative sequence voltage is higher than a threshold. 
     
     
         17 . The computer-implemented method of  claim 15 , further comprising comparing the sampled phase voltages, and determining if an unbalance between the sampled phase voltages is within a pre-defined limit. 
     
     
         18 . The computer-implemented method of  claim 15 , wherein enabling the inter-circuit fault detection scheme further comprises: determining, based on the sampled phase voltages and current, if a fault is within the generator stator. 
     
     
         19 . The computer-implemented method of  claim 15 , wherein enabling the inter-circuit fault detection scheme further comprises: determining, based on the sampled phase voltages, if a fault is a ground fault. 
     
     
         20 . The computer-implemented method of  claim 15 , wherein enabling the inter-circuit fault detection scheme further comprises: determining, based on the sampled phase voltages, if a fault is a phase-phase fault.